Questions[1and1](server)

I've recently upgraded my VPS to a 4cores, 8gb ram and 180gb ssd. This VPS comes with 500 free email accounts with 2gb each. This weekend I will migrate from the old VPS to this new VPS everything, so I will recreate all email accounts, etc, and I am now questioning myself if should I still using the free email accounts or use the VPS as mail server too, the only reason why I would like to have my own mail server is because I would like to authenticate my emails with DKIM and SPF, as some of them are currently going to Spam I believe this will improve the delivery rate. So my question is, is it possible to authenticate those free accounts DKIM and SPF if I have access to the DNS of my domain, please note I have no control at all of those emails, the only control I have is that I can create and delete accounts, but I mean I don't console access or anything to mail server. For your context, the VPS is with 1and1 and the free accounts too.

Please note I have no experience with Mail Servers and DNS, I am php developer.

I'm struggling to configure white labeling between sendgrid and 1and1.com.

Sendgrid asks me to create a variety of subdomains on my domain registrar with specific CNAME values. I'm able to create most of them but I was stuck on:

s1._domainkey.<mydomain>

1and1.com is giving me an "invalid subdomain error. The subdomain could not be created. An error has occurred" Anyone else come across this and resolved it? Do I need to switch registrars?

I can create the subdomain without the underscore but then it doesn't validate against sendgrid.

There's a fairly complex application than runs on two VMs (on Xen). Both VMs run CentOS 6.2 with the exact same packages and configuration for every application running (minus networking which is different). SELinux is disabled on both.

On machine A the application builds perfectly. On machine B when running some tests we get:

ruby[2010] trap invalid opcode ip:7ff9d2944c30 sp:7fff9797e0f8 error:0 in ld-2.12.so[7ff9d2930000+20000]

Digging a bit more to find out where the machines differ, machine A has:

model name : Six-Core AMD Opteron(tm) Processor 2423 HE

and machine B:

model name : AMD Opteron(TM) Processor 6272

I've tried booting machine B with cpuid_mask_cpu=fam_10_rev_c in grub but it did not help either.

So any advice as to how to deal with this, or how to approach the hosting provider so as to run this VM on another physical machine will be greatly appreciated.

Does anyone know how I could setup my 1&1(host) Virtual Private Server account to have sub-domain that points to a specific port on a Windows Server 2008?

So I want http://{something}.{site}.com to be setup to open port 9999 on my webserver at {site}.com.

I need to create an NS record for a domain that is a CNAME, for the purpose of having two domains pointed at one IP, and not having to maintain the current IP address in two different places.

The DNS provider for this domain is DynDNS, but they block this operation:

CNAME cannot be created with label that is equal to zone name

I can do this with another domain whose DNS is served by 1and1:

root@srv-ubuntu:~# dig myseconddomain.co.uk

; <<>> DiG 9.4.2-P1 <<>> myseconddomain.co.uk
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61795
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;myseconddomain.co.uk.             IN      A

;; ANSWER SECTION:
myseconddomain.co.uk.      71605   IN      CNAME   myfirstdomain.co.uk.
myfirstdomain.co.uk.     59      IN      A       www.xxx.yyy.zzz

;; Query time: 298 msec
;; SERVER: 10.0.0.10#53(10.0.0.10)
;; WHEN: Tue Aug 18 14:17:26 2009
;; MSG SIZE  rcvd: 78

Is this a breach of the RFCs or does DynDNS have a legitimate reason for blocking this action?

Followup Thanks to the two answers already posted I now know that 1and1 IS breaching RFCs to do this. However it does work and they seem to support it. For a company that hosts so many domains it seems very odd that they get away with doing this on such a massive scale without objection.

More followup

The output of "dig myseconddomain.co.uk ns" as requested.

root@srv-ubuntu:~# dig myseconddomain.co.uk ns

; <<>> DiG 9.4.2-P1 <<>> myseconddomain.co.uk ns
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18085
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 2

;; QUESTION SECTION:
; myseconddomain.co.uk.             IN      NS

;; ANSWER SECTION:
myseconddomain.co.uk.      4798    IN      NS      ns67.1and1.co.uk.
myseconddomain.co.uk.      4798    IN      NS      ns68.1and1.co.uk.

;; ADDITIONAL SECTION:
ns67.1and1.co.uk.       78798   IN      A       195.20.224.201
ns68.1and1.co.uk.       86400   IN      A       212.227.123.89

;; Query time: 59 msec
;; SERVER: 10.0.0.10#53(10.0.0.10)
;; WHEN: Wed Aug 19 12:54:58 2009
;; MSG SIZE  rcvd: 111